12:00pm - Pizza Lunch
12:15pm - Presentation
"Field-wide Determination of Directional Permeabilities Using Transient Well Testing"
A practical method for estimating the directional permeabilities in anisotropic reservoirs is presented. The method uses pressure-transient-analysis results from at least three sets of interference/pulse tests among wells offset at different azimuths. Knowledge of the maximum/minimum permeability directions in anisotropic reservoirs helps to optimize injectors/producer locations, and is important for reservoir management especially under secondary/enhanced recovery of hydrocarbons. The proposed method uses transient-test data rich with dynamic information aiming to provide field-wide permeability distribution in well-spacing scale, which is relevant for estimating fluids movement and recovery. Its application in a carbonate oil-field in Kazakhstan is also discussed.
The proposed method uses well coordinates and multiple sets of analysis results of interwell transient tests through mathematical matrix operations. The method was validated using synthetic cases, and was applied in Korolev, a naturally fractured reservoir in Kazakhstan. Extensive interwell transient data have been collected and analyzed from carefully designed and conducted tests among 12 wells in Korolev. The permeability-tensor map was generated for the entire field and compared with the fracture orientations derived from geological structure and image-log interpretation. Both static and dynamic data resources indicate fracture orientations vary substantially throughout the field. In some areas, the dominant permeability directions from interwell transient data are consistent with those from image-log. However, they differ in other areas emphasizing the need for using dynamic measurements in well-spacing scale for better understanding of fracture distributions/orientations and their impacts on flow communications among wells.
The novelty of this method of estimating directional permeabilities is that it uses well coordinates and analysis results of individual interwell transient tests directly in heterogeneous reservoirs. It is convenient and efficient. It can be easily used to generate a field-wide permeability-tensor map using dynamic transient data. Its application in a large carbonate reservoir demonstrates its practicality even in fields with complex varying anisotropy. Integrating the results from this method with those from geological and petrophysics analyses reduces uncertainty in reservoir characterization.
Yan Pan is a senior reservoir engineering advisor with Chevron Energy Technology Company based in Houston, TX. Her interest is focused on well testing, production data analysis and dynamic data integration in reservoir models. She has 20 years of industry experience in supporting major assets all over the world through R&D and technical services. She is the 2010 recipient of SPE Western North America Regional Formation Evaluation Award and was selected and served as 2011-2012 SPE Distinguished Lecturer. Yan holds MS and PhD degrees in Petroleum Engineering from Stanford University.